Activities

1. Define mutation.
   
   
2. Define gene.

3. Give at least two examples of mutations in animals (need not be species specific).
   
   
4. Are all gene mutations passed on to offspring? Use evidence to support your response.

5. Explain how mutations can alter a gene.
   
   
6. Explain how mutations are the source of new variations.

Answer Key/Rubric

1. A mutation is a change in the structure in a gene, resulting in a variation that may be transmitted to later offspring.
   
   
2. A gene is a portion of a DNA molecule that can be transferred from a parent to an offspring.
   
   
3. Acceptable responses include, but are not limited to:

• Animals with extra limbs
• Animals with missing limbs
• Animals with size abnormalities (can be unusually large or small)
• Animals with abnormal color or spot patterns
• Animals with different eye colors

4. No, not all mutations are passed on to offspring. Somatic mutations, for example, occur in non-reproductive cells, therefore are not passed on to later generations. If mutations occur in sex cells, then they are passed to offspring which will inherit the genes of the mutation and affect any other offspring.
   
   
5. Mutations of genes occur for a variety of reasons including DNA that copied inaccurately, and external influences. When mutations occur, DNA is sometimes rearranged, new code is inserted, or deleted. When the makeup of the DNA is altered, it changes the components of the gene.  If it occurs on single somatic cells, the change is not passed on to offspring, but when it occurs on reproductive cells, the species’ evolutionary course may be altered.
   
   
6. When the makeup of an organism’s DNA is mutated and involves a reproductive cell, the change then transmitted to any offspring from that parent or future generations. Since DNA is the genetic makeup, any change or shift in is components can alter how the organism looks, behaves functions, etc. potentially changing future generations of that species.